Scratch that — enthusiasts love competitively priced performance cars that won’t require a home equity line of credit to purchase and maintain. Hence the anticipation felt when the words “Toyota FT-86,” “Scion FR-S,” and “Subaru BRZ” flutter into conversations. Who can blame them? Sport compact loyalists and tuner aficionados want to learn about the much-teased two-doors they’d potentially buy soon (or pre-owned in a couple years).Early driving impressions are good so far (read our 2013 Subaru BRZ Prototype First Drive HERE). Unfortunately, we don’t have the cars’ concrete details and specifications just yet; but expect those from the upcoming Tokyo show. However, a few inquisitive minds have shown curiosity over the 2.0-liter boxer engine’s (designated FA) Toyota-sourced fuel injection system. Let’s review what we know, shall we?The PastConsidering the boxer design is signature Subie, it was presumably up to the Ota, Gunma-based automaker’s best to integrate Toyota’s D-4S dual injection system. D-4S is shorter to write out than “direct injection 4-stroke gasoline engine superior version,” and probably more attractive to the marketing team. Apparently, “superior” equals “port injection.”D-4S evolved from the less superior D-4 direct injection system, which was first seen in the Japan-market Corona Premio in 1996. History buffs may recall the Corona, touted as Toyota’s first high-volume car in the United States, was launched stateside in 1965 and was replaced by the Camry for the 1983 model year. In 1997, D-4 earned a Technological Development Award in the 47th JSAE (Society of Automotive Engineers of Japan) Awards in addition to landing on the R&D 100 Awards for R&D Magazine (1 of 3 for Toyota in ‘97). Direct injection is not easy to manage — you must fine-tune particulars like piston crown shape and the injector’s orientation and spray pattern.

D-4 is proficient at stratified-charge, lean-burn operation — it was stingy enough with fuel but troubling from an emissions viewpoint. Higher-than-usual gasoline combustion temperatures (leaner = more parts of air) encourage the production of nitrogen oxide, requiring more involved emissions control. Stratified-charge directs the concentrated air/fuel mixture (mixed inside the combustion chamber) to the spark source, relying on a small, rich mix for flame propagation in an otherwise lean environment.There was more progress during the last decade of the 20th century: Toyota also introduced its D-4D – common-rail direct injection 4-stroke diesel turbo – for diesel vehicles sold outside the U.S.By the 2000s, Toyota brought its stoichiometric D-4 system into the fold, advancing D-4 by attempting to burn gas the familiar homogeneous way – at or around 14.7:1. A homogeneous charge combined with direct injection and properly timed ignition theoretically allows an engine to utilize a high compression ratio, boosting thermal efficiency. The downside? Timing the sequence of fiery events inside the cylinder gets very complicated as the revs increase. The recent wave of improving valvetrain systems isn’t just to procure memorable acronyms either — optimizing variable valve timing and lift actions are critical to eke out efficiency gains across a range of engine speeds.On the diesel front, D-4D Clean Power decided piezoelectric common-rail systems were the way of the future.The PresentBut back to D-4S. As seen in several current Lexus applications, there’s going to be a conventional wet manifold employed simultaneously with direct injection. The port injectors will be key at startup to limit cold-start emissions (the direct injectors briefly fire too). At low and medium loads, the injectors from the port- and direct-injection systems will be continuously spraying together, though the ratio of port-to-direct injection in a single combustion event will vary according to the control units. Running the hybridized injection in the part of the powerband most used by the average consumer is the crux of D-4S, appeasing emissions, fuel consumption, and power demands. At high loads, direct injection takes over fuel delivery responsibilities as minimizing flow loss and aggressive charge cooling take priority.Why bother with port injection at all? In the right condition, the direct/port strategy is capable of putting a uniform air/fuel blend into the chamber that burns neatly, which might not have been possible with either direct or port injection alone. Direct injection in gasoline engines is also known to accelerate carbon buildup because residual products from the combustion process can start to accumulate undesirably, particularly on the intake valve stems. Port injection introduces air and fuel through the intake valve, so any sticking carbon is naturally rinsed off. Will targeting the best of both worlds pay off? We presume Subaru and Toyota would say yes.The Future

There are promising signs from the FA already. Its 7400-rpm redline is clearly higher than the 2012 Impreza’s closely related FB 2.0-liter boxer, which sits in the mid-6000s. Carmakers don’t bump redlines and allow higher engine speeds on a whim, so clearly the FA has to be prepped. Fuel delivery is just one ingredient to an engine’s recipe but as long as everything from the fuel rails to the spark plug heat range and the control software has been chosen appropriately, we should be in for an interesting treat when the BRZ/FT-86/FR-S finally arrives. Especially with the rumor going around that the BRZ is going to pack more than 200 horsepower.None of Subaru’s current products have direct injection. Here’s to a first, even if it’s actually from Toyota.

The Mustang doesn't handle that great? Have you read Mustang reviews? And you haven't driven this thing and there hasn't been any tests of it with performance numbers but you know it will rape V6 Mustangs?
And people say the Camaro ZL1 is overpriced even though it hasn't come out yet. Many criticize cars they don't like even if they don't know enough about them. This isn't specific to GM fans. There was a comment that was praising the WRX so not every one is a "GM fanboy."

It took them so long to make this car because they wanted to get everything right just like the LFA which is doing well without any problems. I think its a good thing to make us wait since it keeps us at the edge of our seats till we get a good look at what the production car along with spec will look like. By time the car comes out we can then see if the alliance of Subaru and toyota long waited coupe paid off.

Once again another moron who somehow makes up facts I love this car. I don't. How cuz I've never driven it you hillbilly. These reason I called you GM fanboys is because no other group of car guys is ignorant and stupid enough to call a car overpriced and overrated before an official price has been announced and before the actual car came out. Damn are Americans getting even dumber? And as much as I love Mustangs this thing will rape V6 Mustangs around the track with less horsepower because lets face the truth, the Mustang isn't that great in handling.

You are a moron super snake, just because someone hates this car, they must be GM rabbits right? Wrong this car sucks its taken way to long to come out, has been dulled compared to some of the first concepts and will have less horsepower and will cost more then a v6 mustang, so stop acting all butthurt cuz someone doesn't like your favorite car.

GM's 2.0T still makes the most of all the turbo-fours minus the Evo, which put out 280 and 300hp respectively. Also, the Subaru 2.5 makes over 300hp. How do you explain all the N/A Hondas tuned out to over 500hp though? You know they've never made a 5.0L anything.

Everyone just needs to chill, the car isn't even out yet, official power/pricing specs haven't even been released!!! If the car is 28k it will still sell. I've seen GTI's that are over 30k!!!! This car is NA and it sounds like the engine could be pushing a little over 200hp, plus in the reviews of the prototype they're saying the car has similar handling to a Porsche Cayman (sounds like a stretch to me too). I'd take RWD NA power over FWD turbo any day of the week. I'm just using an example I'm not saying this is better than a GTI but stop hating on this car....it's about time a car company put together an affordable fun little RWD 2+2 coupe to give to the public, we should applaud Toyota and Subaru for finally giving the us this platform. P.s. an STI concept is already taking shape for those who need more power.

Blah blah blah... A year ago, I was looking forward to see the trim or body shape from both cars, but now it's yawning... I've noticed Subaru has more interest to develop its own tech than Toyota, except for that... what are they calling? oh, yes! D-4S. This sh*t is still a concept, so as posted about it before, I'm gonna get old and production version is not available yet.
Yes, I know my comment sounds troll-ish, but let's face it... I just tell the truth.
-Mönst-

Hey ya know what, nice to see somebody woke up whoever the hell is in control of the products in toyota and we now will soon have a modern day AE86 .
Also, good on subaru's part to join in on the fun, very smart and im sure will be a rewarding decision.
Its also nice to see subaru is moving forward in the performance market & with the STi branding here in the states, and i absolutely cant wait to see the redesigned STi/Wrx, that will be very intresting.
Too Sad Mitsubishi is becoming Honda slowly, by destroying there products hence the Evo becoming hybrid.
:( its a waste really, because the wrx/STi and Evo/ralliart are the only cars sold in the States that are based upon rally cars.

I think it's safe to say that the turbo engine in the WRX is better than the non-turbo, sub-200hp engine in this. Don't tell me this car isn't about horsepower, because I'm saying that for the same money why shouldn't I have more from a proven engine that already is in mass production? The price I've heard that I'm going by is $26k.

You want 100HP per liter, or more, from a naturally aspirated engine?
You're gonna need a state-of-the-art, direct injection fuel system.
Toyota has them. Subaru doesn't.
So to those that say Toyota isn't the brains behind this vehicle........
BD

Correct me if I'm wrong, but you're claiming it will be amazing to drive, without having driven it yourself and whilst calling the people who admit to not knowing how it drives hypocrites?
Then you go on to say Toyota is the innovative company even though Subaru did most of the engineering behind it! lol. You crack me up!

Ouch Super Snake. Zing.
Correct though, nothing in common with the TC, the FT-86 was developed from the ground up, new motor and new frame to keep that weight low. You couldn't fit the TC motor in the FT and I'm pretty sure the drivetrain design is not so simple as to just switch front drive to rear.

Okay GM fanboys stop claiming this thing is overpriced and overrated. Has it been sold yet? Have you driven it yet? No. Exactly shut up just like you're telling people to stop claiming how great it is without ever driving it. You're being hypocrites.
Toyota keeps going with the innovation even if it is mostly Subaru doing the work. And don't bother making some snarky comment about how boring Toyota is with their econo boxes. Those are not the cars I'm talking about. Anyone that knows anything about boxer engines and flat fours will tell you 7400 rpm is ridiculously high. My old Subaru went to like 6,500 or a lil over but the thing was out of power past 6k rpm.

Pricing and some specs are all leaked, but no official specs yet. Therefore, it can still cost less, have a better engine (wtf are you basing that off of?), but will be RWD.
There will be (supposedly) an R Spec, low trim, and high trim versions. I don't recall if the R Spec was supposed to be the stripped version, but I don't think so. For all we know, the claimed approx. $28k maybe for the fully loaded version.
Also, a WRX isn't even in the same category as this thing. At least not the current version. We'll see when they make a new lighter version.

I don't get all the hailing of this "wonderful" car. Few have driven it. We all know automotive journalists often over-hype cars that they like because, well, they're 'new'. The design of toyota (and to a lesser extend the subie) are lack luster at best (save for, perhaps, some snap shots of the interior). Now the discusion of the (correctly branded?) SUPERIOR engine....
Ugh
On paper, before the pictures, this car held promise. Now it seems that it's being so up-lifted that it likely won't live up to the hype.
Then there's the suspected price. Some estimate pushing $30K for some models. Seriously?!? For a RWD glorified TC with a subie engine?
But I bet the youngsters will be lined up - buying into the hype. As usual - fed by the "un-biased" media.